The present invention relates to decorative sheets which are used for the surfaces of furnitures or architectural mounting materials such as wall materials, ceiling materials, counter top materials or the like, and processes for producing them.
As conventional surface decorative sheets, there are mentioned, for example,
(1) a pre-coated paper in which an ordinary printing is provided on a paper base paper and an aminoalkyd resin or an urethane resin is then coated,
(2) a decorative sheet in which in combination with an ordinary printing, an ink comprising a poly(vinyl chloride) resin and containing or not containing a foaming agent is embossed in the form of a pattern on a paper base paper, or
(3) a decorative sheet in which a poly(vinyl chloride) sheet having been sheeted by a calendering method or an extruding method is put into print and then subjected to a heat embossing process.
Among the sheets according to the aforementioned techniques, as for (1), it is difficult to afford an unevenness, i.e., convex-concavity feeling by an ordinary printing and thus it is possible only to express a print of inferior quality as a design. Moreover, since the surface resin layer is very rigid, hard and fragile, it is not desirable to coat it in a large amount. Generally, a paint having a high solid content cannot be designed, and thus it is difficult even to reach the coating in a large amount. Therefore, the sheet according to (1) has a problem that it is difficult to obtain a decorative sheet having excellent wear resistance.
As for (2), it is possible to afford a convex-concavity feeling and to express a print of superior quality as a design. However, since such a sheet comprises a poly(vinyl chloride) resin, it has also a problem that it is difficult to obtain a decorative sheet excellent in wear resistance.
As for (3), a poly(vinyl chloride) sheet is excellent in thermal processability, so that it is possible to afford a convex-concavity feeling and to express a print of superior quality as a design by subjecting the sheet to a heat embossing process. However, such a sheet has problems that it has an insufficient heat resistance and lacks in wear resistance in spite of its softness as a decorative sheet.